Log In New Account Sitemap
  • Home
  • Search
    • Search Collections
    • Map Search
    • Dynamic Species List
    • Exsiccati
    • Taxonomic Explorer
  • Images
    • Image Browser
    • Search Images
  • Species Checklists
    • North America
  • Crowdsource
  • Contacts
    • Partners
  • Acknowledgements
Pteridium aquilinum  
Family: Dennstaedtiaceae
Pteridium aquilinum image
Max Licher
  • FNA
  • Gleason & Cronquist
  • Resources
Carol A. Jacobs
James H. Peck in Flora of North America (vol. 2)
Petioles scattered along creeping stems, 0.3--3.5 m, shallowly to deeply grooved adaxially, base not strongly distinct from stem. Blades broadly deltate, papery to leathery, sparsely to densely hairy abaxially, rarely glabrous. Pinnae often opposite to subopposite [alternate]; proximal pinnae often prolonged basiscopically, each proximal pinna nearly equal to distal part of leaf in size and dissection (except in var. caudata ). Segments alternate, numerous. In accord with the most recent revision (R. M. Tryon 1941) of the genus, Pteridium is treated here as a single widespread species composed of two subspecies with 12 varieties. So treated, it is probably the most widespread species of all vascular plants, with the exception of a few annual weeds (F. H. Perring and B. G. Gardner 1976). The plants are generally aggressive, invading disturbed areas as weeds in pastures, cultivated fields, and roadsides. In Europe, it was harvested and burned to produce potash. Although croziers are eaten in many temperate cultures, bracken has been shown to contain thiaminase (and other compounds with mutagenic and carcinogenic properties). Disagreement exists among taxonomists regarding the rank that should be accorded to the taxa treated herein as varieties. In a survey of the genus, C. N. Page (1976) noted uniform chromosome numbers and flavonoid compositions of the varieties. D. B. Lellinger (1985) separated the genus into at least two species based on morphology, recognizing as species the subspecies of R. M. Tryon (1941). J. T. Mickel and J. M. Beitel (1988) reported sympatric occurrence in Mexico of three taxa that maintained consistent characteristics and only rarely produced plants with combined characteristics. They suggested that these three taxa should be considered as species that occasionally hybridize. P. J. Brownsey (1989) reported that two different brackens in Australia formed sterile hybrids and should be treated as species. Modern systematic studies are needed to evaluate the status and rank of the four North American varieties. As treated below, Pteridium aquilinum var. pubescens , var. latiusculum , and var. pseudocaudatum are in subsp. aquilinum , and var. caudatum is in subsp. caudatum (Linnaeus) Bonaparte.

Vascular plants of NE US and adjacent Canada
Lvs mostly (3-)5-15(-20) dm overall, the erect petiole mostly some-what shorter than the more spreading blade; 2n=104. Many habitats; widespread at least in the N. Hemisphere. Three var. with us:

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.
Pteridium aquilinum
Open Interactive Map
Pteridium aquilinum image
Max Licher
Pteridium aquilinum image
Patrick Alexander
Pteridium aquilinum image
Patrick Alexander
Pteridium aquilinum image
Patrick Alexander
Pteridium aquilinum image
Liz Makings
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Pteridium aquilinum image
Click to Display
100 Initial Images
- - - - -
View All Images

The PCC, and this data portal, were made possible by funding from the National Science Foundation’s Advancing Digitization of Biological Collections (ADBC) program, grant numbers 1802504, 1802352, 1802134, 1802033, 1802270, 1802255, 1802239, 1802446, 1802305.
The pteridoportal taxonomic thesaurus is based on the Checklist of Ferns and Lycophytes of the World, generously provided by Michael Hassler.